Boiler



April 10, 1934. E. A. WEAVER ET AL BOILER Filed March 17. 1932 7 8 nmnfl m z IMW a5 mn m Patented Apr. 10, i934 PATENTW OFFICE BOILER Eastman A. Weaver, Winchester, and Lyman F.

Whitney, Boston, Mass., assignors to Comstock & Westcott, Inc., Boston, Mass.,' a corporation of Massachusetts This invention relates to apparatus for generating fluid pressure, and more particularly to a boiler construction with a related arrangement or a combustion chamber which is particularly suitable in providing vapor for closed systems such as refrigerating systems of the general character disclosed in the copending application of Eastman A. Weaver, Serial No. 73,699, filed August 23, 1924.

In refrigerating systems of this general character mercury is preferred as the propellent fluid which is to be vaporized in the boiler. It is desirable to manufacture systems of this character so that the total quantity of mercury required for the same may be maintained at a um due to the comparatively high cost of his material. Accordingly one of the objects of the present invention is to provides. boiler or vaporizer which will have a small liquid capacity and which will permit the efficient and rapid transfer of heat to the liquid.

In accordance with this invention, the boiler may be arranged to provide a chamber surround ing or substantially enclosing the fire-box or combustlon chamber, and the latter maybe arranged effectively to direct the hot burning gases into contact with a large area of the boiler, thereby ensuring rapid vaporization of the liquid. To

this end the combustion chamber preferably is provided with passages which permit the burn ing gases to sweep in contact with the surface of the fluid containing chamber while following a relativel" indirect or tortuous path between the burner and the outlet flue. Preferably the boiler is formed of cup-like members which provide a chamber substantially enclosing the fire-box except at one end where the burner and exhaust gas flue communicate with the chamber. Thus a relatively large area of the boiler is in direct heat transfer relation to the combustion'chamher. With this arrangement the ratio of the surface oflthe fluid which is in contact with the wall of the combustion chamber is very large in relation to the volume of that fluid. The boiler is provided with means to interconnect all portions thereof and to obviate all possibility of vapor pocketing 'in the same.'

A further object of this invention relates to the provision of a boiler and combustion chamber whichmay be inexpensively manufactured while having high thermal emciency.

In the drawing:

Fig. 1 is a central longitudinal section of a fluid pressure generator showing-combustion a! paratus in elevation;

Application March 17, -19s2, Serial No. 599,604

3 Claims. (c1. 122-23) Fig. .2, is an end elevation showing one end of the fluid pressure generating unit;

Fig. 3 is an elevation of the other end of th fluid pressure generating unit; and

Fig. 4 is a section taken substantially along the 30 line 4-4 of F18. 1.

Referring to the accompanying drawing, which illustrates a preferred embodiment of the invention, it may be seen that the boiler 10 comprises an outer cup-like shell 14 and an inner somewhat smaller cup-like shell 16, the members 14 and 16 being provided with marginal flanges 17 and 18 respectively which are secured to each other, preferably by welding. \Preferably memthe outer shell 14 extends along oppcsiteor upper and lower curved faces of the shell and diametrically across the substantially circular end of the same, Figs. 1 and 3, thus providing a passage which communicates with all parts of the boiler chamber and preventing the ribs 21 and 22 '3 from causing the pocketing of fluid in any part of the boiler. Accordingly a passage is provided which facilitates the flow of vapor to the upper part of the boiler and facilitates the even distribution of liquid in the lower part of the same. The so upper course of the channel 23'may'be somewhat wider than the remainder thereof to receive the ends of the relatively large vapor outlet ducts 26 and 27 which are connectedthereto; A duct 24 is connected to the. lower part of the channel 23 to supply liquid to the boiler.

A casting i1 preferably is disposed within inner shell '16 to provide suitable passages for the flow of burning gases and to facilitate heat conduction to the contents of the boiler. Casting 11 comprises a central tubular section 31 which ex,- tends axially within the boiler and has an open inner end in spaced relation to the end ofthe in ner shell 16, while a web or-flange 32 is integral 65 with the tubular portion 31 and provides a substantially helical passage communicating with the j inner end of the tubular portion-31. The width of flange 32 is so determined that its outer edge firmly contacts the inner surface of shell 16, 1'

thereby facilitating the conduction of heat from the combustion chamber.

The end plate 33 fits within the end of the inner shell 16 and is secured thereto in gas-tight rela tion in any approved manner, preferably by welding. The burner 12 may be received by an opening in the plate 33, the burner tip 13 being engaged with the outer end of the tubular portion 31 of casting 11.

In operation of the apparatus, burning gases from the burner 13 are directed through the central passage 31 against the central portion of the inner shell 16 and the web or flange 32 then guides the flame outwardly from the central por-- tion of the shell 16 along the side walls thereof in atortuous course to the outlet connection 34 and the stack 36.

It will be seen that this improved unit consists essentially of only three parts, namely the inner and outer sections 14 and 16 of the boiler shell and the casting 11, all of which may be readily assembled into a complete unit. The two parts 14 and 16 of the boiler shell may be formed by relatively simple manufacturing operations and-the arrangement of the ribs 21 and 22 assures proper spacing of the respective sections.

It will be evident that this arrangement not only insures the efiective sweeping of the burning gases past substantially the entire inner surface of shell 12 but also that the convolutions of flanges 32 provide excellent, heat conductive means to assist the flow of heat from the burning gases to the boiler chamber. It is thus evident that we have provided a fluid pressure generating apparatus which permits the effective transfer of heat from burning gases directly to a relatively large boiler surface although the boiler itself may contain but a small volume of fluid, and further, that this apparatus is simple and inexpensive to manufacture. a

' We claim:

1. Apparatus of the character described comprising a pair of similarly shaped, concentrically disposed, cup-like shells arranged one within the other, the margins of said shells being integrally joined and their side walls and ends being spaced to provide a fluid receiving chamber, the outer shell having a pressed-out channel portion extending diagonally across its end and along its side wall to a point adjacent to its margin, thereby to provide a vapor-collecting drum, a tubular member concentrically disposed within the inner shell and providing a central passage and an annular combustion chamber between the central passage and the inner shell, the inner end of said tubular member being spaced from the end of said inner shell to provide a communication between the central passage and the annular chamber, a helical flange disposed about said tubular member and defining a helical passage through said combustion chamber, a, discharge flue connected with the outer end of the helical passage,

an inlet duct connected to said channel portion adjacent to the lower end of the outer shell, and an outlet duct connected to said channel portion at a point along the side wall of the outer shell.

2. Apparatus of the character described comprising a pair of similarly shaped, concentrically nesaeee disposed, cup-dike shells arranged one within the other, the margins of said shells being integrally joined and their side walls and ends being spaced to provide a fluid receiving chamber, one of said shells having circumferentially extending spaced ribs which divide said fiuidreceiving chamber into a plurality of annular sections, the outer shell having a pressed-out channel portion extending diagonally across its end and along opposite parts of its side Wall to points adjacent to its margin, thereby providing a vapor-collecting drum at the top of the chamber and a tube at the bottom of the chamber communicating with each of said annular sections, a tubular member concentrically disposed within the inner shell and providing a central passage and an annular combustion chamber between the central passage and the inner shell, the inner end of said tubular member being spaced from the end of said inner shell to provide a communica; tion between the central passage and the annular combustion chamber, a helical flange disposed about said tubular member and defining a helical passage through said combustion char 1'' her, a discharge flue connected with the outer end of the helical passage, an inlet duct con-- nected to said channel portion adjacent to the lower end of the outer shell, and an outlet duct connected to said channel portion at a point along the side wall of the outer shell.

'3. Apparatus of the character described comprising a pair of frustro-conical sheet metal shells concentrically disposed one within the other, the margins of said shells being integrally joined and their side walls and ends being spaced to provide a fluid receiving chamber, one of said shells having circumferentially extending spaced ribs which divide said fluid receiving chamber into a plurality of annular sections, the outer shell having a pressed-out channel portion 652- tending diagonally across its end and along its circular wall to a point adjacent to its margin, thereby to provide a vapor collecting drum at the top of the chamber and a fluid supply tube at the bottom of the chamber communicating with each of said annular sections, a tubular member concentrically disposed within the inner shell and defining a central passage and an annular combustion chamber between the central passage and the inner shell, the inner end of said tubular member being spaced from the end of said inner shell to provide a communication be tween said central passage and annular cornbustion chamber, said tubular member having an integral helical flange with its edge engaging the surface of the wall of the inner shell and thus defining a helical discharge passage through said combustion chamber of gradually increasing cross-sectional area, a discharge flue connected with the outer end of said helical passage, an inlet duct connected to said channel portion adjacent to the lower end of the outer shell, and an outlet duct connected to said channel portion at a point along the side wall of the outer shell.

LYMAN a. Warm n1. EASTMAN A. WEAVER. 

